New methodology for the total synthesis of the cytotoxic sesquiterpene alpha-methylene-gamma-lactones is being worked out, including efficient metal-promoted techniques. Strategies for application of these methods to the preparation of simple natural products such as confertin are being pursued. The synthesis of alnusone is essentially complete and will provide the basis for an expanded effort in the synthesis of naturally occurring cyclic biphenyl derivatives. Synthetic efforts directed toward steganone, another cyclic biphenyl compound and of interest as an anti-tumor agent, are being directed along a path involving a deuterium isotope effect as a key step. BIBLIOGRAPHIC REFERENCES: M.F. Semmelhack and R.D. Stauffer, "Reactions with Copper Hydride-New Preparative and Mechanistic Aspects", J. Org. Chem., 40, 3619 (1975). M.F. Semmelhack and E.S.C. Wu, "Synthetic Methods for Sesquiterpene Methylene-lactones", J. Amer. Chem. Soc., 98, 3384 (1976).